Evening I'm having a little issue but first, background so you know what I'm trying to achieve. We have a customer who wants to use 2 VOIP trunks and extentions have their own DDI/Caller ID numbers setup. The issue I face is that one trunk needs outbound caller ID format to be in standard UK format ie 01234123456 and the other can only accept international format outbound caller id ie 441234123456. So for one of the trunks, I need to setup outbound caller ID reformatting. I've confirmed both trunks accept outbound calls if I manually specify the correct caller ID format in the extension so know that the issue isn't with the trunk setup itself. I've tried setting up outbound caller ID reformatting - essentially with a rule that just replaces the 0 with 44 - the way I understood the 3CX page on reformatting was that I should be able to achieve this with the following: Source CID pattern: 0(.*) New Source CID pattern: 44\1 This doesn't seem to work however - the number keeps being presented as per the extension caller ID. Do I need to set a specific outbound parameter as well or have I just got the reformatting rule parameters wrong? Outbound parameter at the moment is set to take the extension caller ID part and my understanding was that the reformatting rule would change this for the trunk that requires 44. Any and all help/guidance most appreciated.